import time
incomplete_sign=50
print('='*23+'开始下载'+'='*25)
for i in range(incomplete_sign+1):
    completed ="*" * i
    incomplete ='.' * (incomplete_sign-i)
    percentage =(i /incomplete_sign) * 100
    print("\r{:.0f}%[{}{}]".format(percentage,completed,incomplete),end="")
    time.sleep(0.3)
print("\n" + '='*23+'下载完成'+'='*25)